WO2015052309A1

WO2015052309A1 - Method for forming a tube from a flat web material, and a tube forming device and a system for producing bags

Info

Publication number: WO2015052309A1
Application number: PCT/EP2014/071726
Authority: WO
Inventors: Uwe WOLFRAM
Original assignee: Windmöller & Hölscher Kg
Priority date: 2013-10-11
Filing date: 2014-10-10
Publication date: 2015-04-16
Also published as: EP3055126A1; DE102013220512A1; US10526158B2; US20160250818A1; CN105722672B; CN105722672A; EP3055126B1

Abstract

The invention describes a method for forming a tube from a flat web material, in which method a flat web is fed in by means of feeding devices, the edges of the flat web material are turned in by way of at least one tube forming tool, wherein the edge regions subsequently overlap, and parts of the overlapping edge regions are joined to one another. The desired position of at least one edge after turning in of the edges is fixed, the actual position of at least one edge is determined by means of a measuring device and, in the case of a deviation of the actual position from the desired position, the tube forming tool is moved at least transversely with respect to the transport direction of the flat web material by means of an actuating device.

Description

A method of forming a hose from a flat web material, and a hose forming device and a system for making bags

The invention relates to a method for forming a tube from a flat sheet material according to the preamble of patent claim 1 and a hose forming device according to the preamble of claim 9. Furthermore, the invention relates to a system for producing bags according to the preamble of claim 17. A semi-finished in the manufacture of Bags and sacks are pieces of hose that are often separated from a hose, for example cut or torn off. Such hoses are made by a method and apparatus for making a hose from a flat web material by feeding this flat web with feeders such as idler rolls. The flat web material in this case has a surface which is bounded by the side edges or edges. With hoses forming tools then the edges, which are also referred to as side edges, hammered inwards, in such a way that the edge areas overlap each other. Parts of the overlapping edge areas are connected to each other. This can be done for example by introducing an adhesive substance (hot melt adhesive, cold glue, plastic melt) between the individual of the overlapping edge regions. A connection can also be made by contact welding, hot air sealing or even by sewing. The actual hose is shaped with it. The tube forming tools include, for example, baffles and rods for turning the edges and other leadership facilities. Folding, holding and pressing tools can also count. Other tube forming tools may be gusseted, which also allows gussets to be inserted into the tube during actual tube formation to later produce gusseted bags or sacks. All these tools are usually fixed, but can be moved to set up the hose production. hand-operated

Fasteners such as hand screws are common. Once the hose-forming device has been set up for production, generally nothing has to be changed. In a continuous process, the hose is now formed.

However, it may happen that the flat web material used is not sufficiently homogeneous over its entire width and / or its entire length. Since quite high transverse forces act on the flat web material in the hose-forming device, uncontrolled and thus undesirable displacements of the material may occur transversely to its transport direction, which leads to different envelope widths. This then results in a deviation from the nominal geometry of the hose, which manifests itself, for example, in the fact that the seam of the hose does not lie at the desired position but is displaced transversely to the extension direction of the hose.

This is not only unpleasant when it comes to the fact that imprints are to be positioned correctly with respect to the tube edges. It is particularly problematic if the flat web material was processed before the formation of the tube for later bag or bag making, but these processing positions are not arranged in the correct position with respect to the tube edges. The later sacks or bags may be faulty.

The object of the present invention is therefore to propose a method and a device with which the disadvantages described above can be avoided. According to the invention, this object is solved by the features of claim 1. Based on the above-described prior art, the object is achieved in that the desired position of an edge is determined, which should result after the folding of the edges. This target position can be entered into a control device, for example, by entering a numerical value indicating the absolute position or the relative position with respect to a stationary component. Also, the clamping of the flat web material in the tube forming device with a correct positioning can be understood as setting the target value. This clamping is usually done at a standstill, ie before the start of production.

According to the invention, the actual position of the edge is determined by means of a measuring device. If the desired position and the actual position deviate from one another, then the hose-forming tool or the hose-forming tools is displaced transversely to the transport direction of the flat web material. The flat web material in front of the actual hose-forming device is thus not displaced, but rather the instationary states occurring in the actual hose-forming process are compensated by the fact that the hose-forming tool tracks the actual position of the edge. If the measuring device is also simultaneously carried along, the actual position becomes the new desired position after correction has taken place. This process can be repeated several times during an order processing. In this case it is not necessary to enter the absolute target position. By this procedure it is achieved that with the displacement of the hose forming tool, the relative position of the side edges of the later hose the edge or the edges, as far as they have moved transversely, is also moved transversely. The hose will therefore always have the same position of the seam relative to its side edges over its entire length - with the exception of minor deviations. Imprints and processing positions will now be found again at the same points across the hose length extension. Particular advantages of the invention in connection with the production of hoses, which consist of a flat web material comprising a plastic fabric. This plastic fabric often comprises polyolefinic material, such as polypropylene, and is made by making stretched ribbons, often 2 to 5 mm wide, of this material into a round or flat weave. A round fabric can first be laid flat and separated by trimming or cutting in the edges to flat web material. Also, a one-sided trimming or slicing and a striking of the two layers are conceivable in principle to obtain a flat web material. This flat sheet material is often provided with a coating. This coating is advantageously formed from a plastic which has a lower melting temperature than the fabric material. Thus, it is possible for the production of sacks or bags parts of the hose pieces permanently connected by hot air sealing together without the fabric material is excessively heated in the sealing process, because the fabric material would then lose its strength.

The coating of the fabric material also has the advantages that it is easy and high quality printable and that it serves as a moisture barrier. Tissue material per se has the advantage that it has a comparable strength compared to a normal plastic film with less material used. However, it is extremely complicated to produce the fabric and in particular the coating homogeneously, so that qualitatively satisfactory hoses could be produced in a tube forming device according to the prior art. The reason for this is that, for example, the fabric often has a "twist" in the circumferential direction (longitudinal strips are tilted in the direction of transport) and, above all, the coating can not be produced over the width of the flat web material with a constant thickness occurring and already described above, therefore, have a particularly negative impact on coated fabric material Tubing device according to the invention and the method according to the invention, which is advantageously carried out with a flat web material made of coated fabric, fabric tubes can be produced which avoid the above-mentioned disadvantages and which are ideal for the production of bags or sacks.

It is further advantageous if the flat web material is provided with perforation cuts before it is formed into a tube. Such perforation cuts can be produced with a knife roller which acts against a counter-roller guiding the flat web material. There are also non-contact and thus low-wear methods and devices advantageous, such as a laser beam assembly. The invention offers particular advantages when such perforation cuts are staggered, d. H. Seen in the longitudinal direction are arranged at different positions. Such staggering perforations are often introduced into the flat web material in order to produce durable and particularly dense bottoms of sacks or bags. A manufacturing method for these bags is shown in EP 1 228 857. The description of the relay sections included therein is hereby content of the invention disclosed with this patent application. It is easy to see that the stubble cut must correspond to the rebate edges of the tube, d. H. the jumps between each section of the cut should be on the edges of the tube to make a proper sack. In the prior art, on the other hand, by "rolling" the flat web material during tube formation in the transverse direction, the staggering perforation is displaced beyond the later edges, ie, the staggering perforation lies transversely offset from the edges of the tube the present invention in connection with perforation cuts, especially with staff cuts.

In an advantageous embodiment of the invention it is provided that the at least one hose forming tool is arranged on a frame and that this frame is moved. A movement takes place when a deviation from target and actual position is detected. Advantageously, that carries Frame all hose forming tools and also means for connecting the overlapping in the hose forming process edge areas. To move the frame then only a single displacement drive is required, for example, an electric motor which acts on a spindle-spindle nut combination. The number and mounting positions of the hose forming tools can be varied in this approach in large bandwidths.

An advantageous embodiment of the invention also provides for the use of an ultrasonic sensor or an electro-optical sensor as a measuring device. As a rule, these sensors comprise a transmitter which, for example, emits ultrasonic waves or electro-optical radiation. Opposite this transmitter, a flat receiver is arranged, which provides a value depending on the intensity of the received waves or radiation, for example, a current value or a voltage value. If now a part of the receiver surface is covered, the value decreases in proportion to the size of the covered part of the receiver surface. Transmitter and receiver are arranged relative to each other immovable. The at least one edge of the flat web material is guided between the transmitter and the receiver. In the basic setting of the method according to the invention, the sensor is positioned before the actual production start of the tube, ie preferably at standstill, the transmitter-receiver unit so that half of the receiver surface is covered as possible, so that the change of the value is detectable in both directions , That is, an increase in the value is observed when the edge portion of the flat sheet material releases a larger sensor area and a decrease in value when the edge of the flat sheet material covers a larger area. The measured value is thus in relation to the deviation. The desired position of the flat web material is now either determined by covering, for example, a predetermined proportion of the receiver surface or that after the device of the flat web material of the covered portion of the receiver surface is determined and communicated to the controller. If, during operation, a deviation from the desired position, that is a deviation from the set value, results simultaneously in order to displace the at least one hose-forming tool, the transmitter-receiver unit, that is to say the sensor, can also be displaced so that subsequently the previously set portion of the receiver surface is covered again. This can be achieved in a particularly advantageous manner by an arrangement of the sensor on the frame when the frame is moved for the purpose of displacement of the hose forming tool. In the formation of a tube of flat web material, in which a staggered cut or a staggering perforation is introduced, it is advantageous to make the correction when the actual position deviates from the desired position by 2 mm. Otherwise, the tightness of the later sacks or bags would no longer be guaranteed with this or a greater deviation.

The actual position of the edge is preferably arranged at a position within the tube forming device - viewed in the transport direction of the flat web material - in which the edge regions of the flat web material have already been overlapped and preferably not yet connected to one another. In other words, the shape of the tube is almost complete at this position, but the permanent connection of the edge regions is still outstanding. Especially at this position, the effects of the transverse forces within the tube forming process can be determined with utmost certainty. In addition, the adjustment is easy at this point, especially since only a few adjustment means are needed.

The above object is also achieved by a hose forming device comprising the features of claim 9. Accordingly, a tube forming means for forming a tube from a flat web material, which at least one feed means for supplying a flat web, at least one hose forming tool for driving the side edges of the flat web, wherein then overlap the edges and at least one means for connecting parts of the overlapping edges according to the invention further developed in that a device is provided, with which the desired position of at least one edge can be fixed after the edges are turned in, that a measuring device for determining the actual position of at least one edge and that an adjusting device for moving the hose forming tools are provided at least transversely to the transport direction of the flat web material in a deviation of the actual position of the desired position.

The movement takes place relative to the flat web material in the feed or relative to the at least one feed device which guides the flat web material.

The features described in connection with the method according to the invention can also be components of a device according to the invention, so that they can also be brought into connection with the device according to the invention. Likewise, in connection with the device according to the invention, disclosed features of a method according to the invention can be represented, so that it is likewise possible to resort to this.

The subject matter of the invention is furthermore a system for the production of sacks or bags according to claim 17. This object solves the problem that sacks or bags may be of reduced quality if the tube transversally shifts within the tube forming device and thus the bag or sack bottoms can be formed demanding.

A soil preparation device, which may be part of a system according to the invention, is described in DE 10 2009 056 078 A1. This disclosure is hereby incorporated by reference into the present disclosure.

The above-mentioned object is achieved in that a tube forming device as described above (in particular according to claims 9 to 16) is provided as tube forming device.

Further embodiments of the invention will become apparent from the description and the claims. The individual figures show:

Fig. 1 side view of an inventive

Hose educational institution

Fig. 2 top view of a hose forming device according to the invention

Fig. 3 view of the section A-A in Fig. 1st 1 shows a side view of a hose forming device 1 according to the invention. The hose machine comprising the hose forming device initially comprises an unwinding device 2, in which a winding 3 of a flat web material 4 rotates in the direction of the arrow 5. The flat web material 4 is guided over a deflecting roller 6, which represents a simple example of a feeding device of the flat web material 4 to the hose forming device 1.

The guide roller 6 is shown in this embodiment as a counter roller for the knife roller 7, with which perforations can be introduced into the flat web material. The knife roller 7 carries one or more perforating knives 8. The functions of the deflecting roller 6, that is to say "deflecting" and "providing counter-pressure in the perforating process", are here combined only for the sake of clarity, in practice these are rather separated. The actual tube forming process begins already in the area between the guide roller 6 and the tube forming device 1 by the edges 10 and 1 1 are guided upwards, ie in the direction z. In this case, for example, the pressure roller 12, which holds the central part of the flat web material 4 at a fixed position with respect to the z-axis, and guide plates 13, which laterally apply guide forces for the flat web material from the outside. Pressure roller 12 and guide plates 13 are examples of a variety of possible tube forming tools that can be used to give the desired appearance to the later tube. Further examples of hose forming tools have already been given in the general description of the invention. All these Hose forming tools are arranged on the frame 15, wherein the hose forming tools for the purpose of adjustment or for the purpose of production preparation by means of suitable adjusting and fastening devices can be moved relative to the frame and then attached.

The example of the guide plates 13 is easy to see that the flat web material lateral forces are imposed, which may have a displacement of the tube in the z and / or y-direction result.

FIG. 3 shows further tube forming tools which may be referred to as gussetters 14. The gussets 18 which can be produced in this way are preferably used for the production of specific bags or sacks, since after filling thereof, almost a cuboid is formed, which offers advantages in storage and transport. Straight tubes with side edges are particularly advantageous to produce a device according to the invention with a method according to the invention, since it arrives at the correct position of the edges after the tube formation especially in gusseted tubes, especially if they include staggered perforations.

In the further course of the tube formation process, the edge regions of the flat web material overlap one another, so that even the cross-sectional contour represents a hose which is still open in the longitudinal direction. This can be clearly seen in FIG. The overlapping region 16 of the edge regions or the edges of the flat web material 4 can be seen in FIG. The outer folded edges of the tube may also be referred to as lateral or outer edges 17. In the further course of the hose transport in the direction z, the sensor unit 20 follows, which is clearly visible in FIG. This comprises a mounted on the frame 15, U-shaped profile 21, which carries the transmitter 22 and the receiver 23 of the sensor. The hose forming tools are arranged and arranged so that the edge 1 1 between transmitter 22 and Receiver 23 passes through. A change in position of the edge 1 1 in the y direction can thus be detected by the sensor, wherein the sensor is set up so that it can determine the magnitude of the position change. The receiver sends corresponding values or signals via a data line 24 to the control unit 25. This converts this information into a control information, which is sent via the control line 26 to the actuator 27.

The actuator is fixed - for example, by screwing with the hall floor - arranged and causes a shift of the frame in the y-direction via sliding elements. The actuator may be, for example, a rotating electric motor, which acts on the frame 15 via gear elements 28, such as a spindle-spindle nut arrangement or a toothed rack and pinion arrangement. A linear drive, for example a linear electric motor, is conceivable and would also do without gear elements.

The frame 15 is supported on slides 30, which in turn rest on guide rails 31 and are slidable along this. The contact between carriage and guide rails can be formed from sliding or rolling elements.

For the completion of the tube 9 is still a permanent connection of overlapping in the overlap region 16 edge regions of the already formed flat sheet material 4 is necessary. For this purpose, an extrusion device 32 is provided, with which molten plastic can be applied in the overlapping region 16 between the edge regions. With an adjoining in the x-direction, but not shown pressure roller of the overlap region is then compressed, so that this results in and after the cooling of the plastic, a firm connection. But there are also many other types of connection conceivable.

The now finished tube 9 is usually converted in the winding device 33 to the hose reel 34 (see Figure 1), which then, for example, a Bag machine can be supplied. However, it is also conceivable that the tube machine directly connects a further processing machine, without a hose reel would have to be formed.

LIST OF REFERENCE NUMBERS

Schlauchbildungseinnchtung

Winding up 2

reel

Flat sheet

Arrow (direction of rotation of the roll 3)

deflecting

knife roll

perforating

tube

edge

capstan

guide plate

Gusseted depositors

frame

overlap area

Side or outside edges

gusseted

sensor unit

U-shaped profile

transmitter

receiver

data line

control unit

control line

actuator

transmission elements

carriage

guide rail Extrusionseinnchtung

Wickeleinnchtung

hose reel

Claims

Patent claims

1 . Method for forming a tube from a flat sheet material, in which

• a flat web is fed using feed devices,

• the edges of the flat web material are folded in by at least one tube forming tool, with the edge regions then overlapping,

• Parts of the overlapping edge areas are connected to one another,

characterized,

• that the target position of at least one edge is determined after the edges have been folded in,

• that the actual position of at least one edge is determined by means of a measuring device and

• that if the actual position deviates from the target position, the tube forming tool is moved at least transversely to the transport direction of the flat web material by means of an adjusting device.

2. Method according to claim 1,

characterized in that

A plastic fabric is supplied as flat web material.

3. Method according to one of the preceding claims,

characterized in that

A coated plastic fabric is supplied as the flat web material.

4. Method according to one of the preceding claims,

characterized in that

the flat web material is provided with perforation cuts before the tube is formed.

5. Method according to one of the preceding claims,

characterized in that

the tube forming tool is arranged on a frame and that the frame is moved.

6. Method according to one of the preceding claims,

characterized in that

An ultrasonic sensor or an electro-optical sensor is used as the measuring device.

7. Method according to one of the preceding claims,

characterized in that

the actual position of the edge is determined after the edges of the flat sheet have been brought into the overlap.

8. Method according to one of the preceding claims,

characterized in that

the actual position of the edge is determined before the overlapping edges are connected to one another.

9. Tube forming device for forming a tube from a flat web material, comprising:

• at least one feed device for feeding a flat web,

• at least one tube forming tool for driving in the side edges of the flat sheet, with the edge areas then overlapping,

• at least one device for connecting parts of the overlapping edge areas,

marked by

• a device is provided with which the target position of at least one edge can be determined after the edges have been folded in,

• a measuring device for determining the actual position of at least one edge, and

• an adjusting device for moving the tube forming tool at least transversely to the transport direction of the flat web material if the actual position deviates from the target position.

Tube forming device according to the preceding claim,

characterized in that

the feed device comprises a device for introducing perforation cuts into the flat web material.

1 1 . Tube forming device according to one of the two preceding claims, characterized in that

the tube forming tool is arranged on a frame and that the frame is displaceably arranged.

12. Hose forming device according to the preceding claim,

characterized in that

Guide devices are provided which extend essentially transversely to the transport direction of the flat web and that the frame comprises carriages which are displaceable on the guide devices.

13. Hose forming device according to one of the four preceding claims, characterized in that

An ultrasonic sensor or an electro-optical sensor is provided as the measuring device.

14. Tube forming device according to one of the five preceding claims, characterized in that

the measuring device is arranged behind the tube forming tools when viewed in the transport direction of the flat web.

15. Tube forming device according to one of the six preceding claims, characterized in that

the measuring device, viewed in the transport direction of the flat web, is arranged in front of the device for connecting parts of the overlapping edges.

16. Tube forming device according to one of the seven preceding claims, characterized in that

a control device is provided, to which the actual position of the at least one edge can be transmitted by the measuring device, with which this actual position is comparable to the target position and with which control signals can be transmitted to the adjusting device.

17. System for making bags, comprising

a tube forming device for forming a tube from a flat web material,

a separating device for separating the hose into hose pieces,

a base manufacturing device with which a base can be formed on at least one end of the hose pieces,

marked by

a tube forming device according to one of claims 9 - 16.